PRTN3 and interstitial lung disease: Within the serological data available, the most frequent positive autoantibodies found in AD-ILD patients were ANA (71.1%), myositis-associated antibodies (47.3%), ACPA (42.4%), RF (39.2%), anti-SSa/Ro (32.1%) and anti-Scl 70 (24.6%) (Table 2).